STEAM TURBINE POWER GENERATION FACILITY USING OXYGEN-HYDROGEN COMBUSTION

Abstract

A steam turbine power generation facility in an embodiment includes: a steam generator that generates steam by heat of reaction generated by combustion of oxygen and hydrogen; a high-pressure steam turbine into which steam is introduced from the steam generator; a combustor into which steam discharged from the high-pressure steam turbine is introduced and that combusts oxygen and hydrogen to reheat the introduced steam; a low-pressure steam turbine into which steam discharged from the combustor is introduced and into which steam discharged from the high-pressure turbine is introduced as a cooling medium; and a condenser that condenses steam discharged from the low-pressure steam turbine.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2022-132711, filed on Aug. 23, 2022; the entire contents of which are incorporated herein by reference.

FIELD

Embodiments of the present invention relate to a steam turbine power generation facility using oxygen-hydrogen combustion.

BACKGROUND

Conventional thermal power generation facilities include a steam power generation facility including a boiler and a steam turbine, a gas turbine combined cycle power generation facility including a gas turbine, a heat recovery steam generator (HRSG), and a steam turbine, and so on.

In the conventional thermal power generation facility, the steam to be introduced into the steam turbine is produced in the boiler or heat recovery steam generator. In the boiler of the steam power generation facility, feedwater is heated by heat exchange with a combustion gas to generate steam. In the heat recovery steam generator of the gas turbine combined cycle power generation facility, feedwater is heated by heat exchange with an exhaust gas discharged from the gas turbine to generate steam. As above, in the conventional thermal power generation facilities, the feedwater is evaporated using the heat quantity obtained by the heat exchange with a high-temperature gas to generate steam.

In the conventional thermal power generation facilities described above, the high-temperature gas utilized for generating steam is exhausted after heat exchange. In general, of all the heat losses in boilers and heat recovery steam generators, the heat loss due to exhaust heat is said to be the largest.

Further, in the conventional thermal power generation facilities, the high-temperature gas is produced by combustion of fossil fuels and air. As a result, the high-temperature gas contains carbon dioxide (CO₂), nitrogen oxides (NO_x), and so on. In recent years, efforts have been made to achieve carbon neutrality, which means reducing greenhouse effect gas emissions to essentially zero, and the regulations on emissions of carbon dioxide (CO₂), nitrogen oxides (NO_x), and other gases are becoming increasingly strict.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a system diagram schematically illustrating a configuration of a steam turbine power generation facility in a first embodiment.

FIG. 2 is a system diagram schematically illustrating another form in the steam turbine power generation facility in the first embodiment.

FIG. 3 is a system diagram schematically illustrating another form in the steam turbine power generation facility in the first embodiment.

FIG. 4 is a system diagram schematically illustrating another form in the steam turbine power generation facility in the first embodiment.

FIG. 5 is a system diagram schematically illustrating a configuration of a steam turbine power generation facility in a second embodiment.

FIG. 6 is a system diagram schematically illustrating another form in the steam turbine power generation facility in the second embodiment.

FIG. 7 is a system diagram schematically illustrating a configuration of a steam turbine power generation facility in a third embodiment.

FIG. 8 is a system diagram schematically illustrating another form in the steam turbine power generation facility in the third embodiment.

FIG. 9 is a system diagram schematically illustrating a configuration of a steam turbine power generation facility in a fourth embodiment.

FIG. 10 is a system diagram schematically illustrating another form in the steam turbine power generation facility in the fourth embodiment.

FIG. 11 is a system diagram schematically illustrating a configuration of a steam turbine power generation facility in a fifth embodiment.

FIG. 12 is a system diagram schematically illustrating another form in the steam turbine power generation facility in the fifth embodiment.

FIG. 13 is a system diagram schematically illustrating another form in the steam turbine power generation facility in the fifth embodiment.

FIG. 14 is a system diagram schematically illustrating a configuration of a steam turbine power generation facility in a sixth embodiment.

FIG. 15 is a system diagram schematically illustrating another form in the steam turbine power generation facility in the sixth embodiment.

FIG. 16 is a system diagram schematically illustrating a configuration of a steam turbine power generation facility in a seventh embodiment.

FIG. 17 is a system diagram schematically illustrating another form in the steam turbine power generation facility in the seventh embodiment.

FIG. 18 is a system diagram schematically illustrating another form in the steam turbine power generation facility in the seventh embodiment.

DETAILED DESCRIPTION

There will be explained embodiments of the present invention below with reference to the drawings.

In one embodiment, a steam turbine power generation facility using oxygen-hydrogen combustion in an embodiment includes: a steam generator that generates steam by heat of reaction generated by combustion of oxygen and hydrogen; a first steam turbine into which steam is introduced from the steam generator; a first combustor into which steam discharged from the first steam turbine is introduced and that combusts oxygen and hydrogen to reheat the introduced steam; a second steam turbine into which steam discharged from the first combustor is introduced; and a condenser that condenses steam discharged from the second steam turbine.

First Embodiment

FIG. 1 is a system diagram schematically illustrating a configuration of a steam

turbine power generation facility 1 in a first embodiment. Incidentally, the steam turbine power generation facility 1 functions as a steam turbine power generation facility using oxygen-hydrogen combustion.

As illustrated in FIG. 1, the steam turbine power generation facility 1 includes a steam generator 10, a steam turbine system 20, and a power generator 50 as main components.

The steam generator 10 generates steam using the heat of reaction generated by the combustion of oxygen and hydrogen. The steam generator 10 includes a hydrogen supply part 11 that supplies hydrogen, an oxygen supply part 12 that supplies oxygen, and a feedwater supply part 13 that supplies feedwater to be steam. The feedwater supply part 13 supplies the feedwater supplied via a later-described feed pipe 39 into water vapor produced by the combustion of oxygen and hydrogen.

In the steam generator 10, water vapor is produced by the combustion of oxygen and hydrogen, and at the same time, steam is generated from the feedwater by the heat of reaction between oxygen and hydrogen. That is, the medium to be discharged from the steam generator 10 is steam. Incidentally, the flow rates of oxygen and hydrogen to be supplied to the steam generator 10 are adjusted as appropriate based on, for example, setting the temperature of the water vapor to be produced, or the like. The flow rates of oxygen and hydrogen are adjusted, for example, to achieve a stoichiometric mixture ratio (equivalence ratio of 1). Incidentally, the equivalence ratio mentioned here is an equivalence ratio calculated based on the fuel flow rate and the oxygen flow rate.

The steam turbine system 20 includes a high-pressure turbine 21, a low-pressure turbine 22, a condenser 23, a combustor 30, a feed pump 24, and a feedwater heater 25. Incidentally, the high-pressure turbine 21 functions as a first steam turbine, and the low-pressure turbine 22 functions as a second steam turbine. The combustor 30 functions as a first combustor.

In the flow direction of a steam flow, the low-pressure turbine 22 is provided downstream of the high-pressure turbine 21. The high-pressure turbine 21, the low-pressure turbine 22, and the power generator 50 are arranged, for example, on the same axis and are configured so that their rotors rotate integrally. Incidentally, in FIG. 1, the rotors are illustrated by dashed lines.

The steam inlet of the high-pressure turbine 21 is connected to the steam generator 10 via a main steam pipe 35. The steam outlet of the high-pressure turbine 21 is connected to the low-pressure turbine 22 via a steam pipe 36.

The combustor 30 combusts oxygen and hydrogen. The combustor 30 is interposed in the steam pipe 36, for example. The combustor 30 includes a hydrogen supply part 31 that supplies hydrogen, and an oxygen supply part 32 that supplies oxygen. In the combustor 30, water vapor is produced as a combustion gas.

Further, the steam discharged from the high-pressure turbine 21 is introduced into the combustor 30. The combustor 30 reheats the introduced steam by the produced water vapor.

Incidentally, the flow rates of oxygen and hydrogen to be supplied to the combustor 30 are adjusted as appropriate based on, for example, setting the temperature of the water vapor to be produced, or the like. The flow rates of oxygen and hydrogen are adjusted, for example, to achieve a stoichiometric mixture ratio (equivalence ratio of 1). Further, the example where the combustor 30 is interposed in the steam pipe 36 is explained, but the combustor 30 may be provided at the steam inlet portion of the low-pressure turbine 22.

The steam inlet of the low-pressure turbine 22 is connected to the combustor 30 via the steam pipe 36. Further, a portion of the steam discharged from the high-pressure turbine 21 is introduced as a cooling medium into the low-pressure turbine 22 via a cooling medium supply pipe 37. One end of the cooling medium supply pipe 37 is connected to the steam pipe 36, for example, between the high-pressure turbine 21 and the combustor 30. The other end of the cooling medium supply pipe 37 is connected to a cooling medium introducing portion of the low-pressure turbine 22.

Incidentally, although not illustrated, a flow rate regulating valve for regulating

the flow rate of the cooling medium to be introduced into the low-pressure turbine 22 is interposed in the cooling medium supply pipe 37. The temperature of the cooling medium is lower than that of the steam to be introduced into the low-pressure turbine 22 from the combustor 30. The temperature of the cooling medium is set, for example, to a temperature that can maintain the components of the low-pressure turbine 22 at or below the heat-resistant temperature of the components.

The cooling medium is introduced into the low-pressure turbine 22, thereby making it possible to cool the components of the low-pressure turbine 22. This allows the steam that is introduced from the combustor 30 to be hotter.

The steam outlet of the low-pressure turbine 22 is connected to the condenser 23 via an exhaust pipe 38. The condenser 23 is connected to the feedwater supply part 13 of the steam generator 10 via the feed pipe 39. For example, the feed pump 24 and the feedwater heater 25 are interposed in the feed pipe 39.

The feed pump 24 pumps the condensed water produced in the condenser 23 to the steam generator 10 as feedwater. The feedwater heater 25 is connected to the low-pressure turbine 22 via an extraction steam pipe 40. Extraction steam from the low-pressure turbine 22 is introduced into the feedwater heater 25 via the extraction steam pipe 40.

Here, FIG. 1 illustrates an example where an attemperator 110 is provided in the extraction steam pipe 40. The attemperator 110 has a function of reducing the temperature of the extraction steam flowing through the extraction steam pipe 40. The attemperator 110 is formed of a heat exchanger that exchanges heat between the extraction steam flowing through the extraction steam pipe 40 and feedwater. A feedwater lead-out pipe 111 that leads out feedwater from the feed pipe 39 to the attemperator 110 and a feedwater introduction pipe 112 that introduces feedwater into the feed pipe 39 from the attemperator 110 are connected to the attemperator 110. The feedwater introduction pipe 112 is connected to the feed pipe 39 downstream of the feedwater lead-out pipe 111. Incidentally, the temperature of the feedwater to be led out to the attemperator 110 via the feedwater lead-out pipe 111 is lower than that of the extraction steam flowing through the extraction steam pipe 40.

The feedwater that has led out from the feed pipe 39 to the attemperator 110 via the feedwater lead-out pipe 111 exchanges heat with the extraction steam flowing through the extraction steam pipe 40 to reduce the temperature of the extraction steam. Incidentally, the temperature of the feedwater increases as a result of the heat exchange with the extraction steam. The feedwater whose temperature has increased is introduced into the feed pipe 39 via the feedwater introduction pipe 112.

High-temperature steam obtained by reheating the steam exhausted from the high-pressure turbine 21 in the combustor 30 is introduced into the low-pressure turbine 22. Therefore, depending on the extraction steam conditions, the temperature of the extraction steam flowing through the extraction steam pipe 40 may exceed the temperature required by the feedwater heater 25. In such a case, providing the attemperator 110 makes it possible to increase the temperature of the feedwater and at the same time, to reduce the temperature of the extraction steam to be introduced into the feedwater heater 25 down to an appropriate temperature. Incidentally, an example where the attemperator 110 is provided in the extraction steam pipe 40 has been explained here, but the extraction steam pipe 40 can also be configured without providing the attemperator 110 depending on the extraction steam conditions.

The feedwater heater 25 is connected to the condenser 23 via a discharge pipe 41, for example. The extraction steam that has heated the feedwater is introduced into the condenser 23 via the discharge pipe 41, for example. Incidentally, the extraction steam that has heated the feedwater may be introduced into the feed pipe 39 upstream or downstream of the feed pump 24. Incidentally, the feedwater heater 25 may be configured to have a deaeration function.

Here, a plurality of feed pumps may be provided in the feed pipe 39. Depending on the pressure of the feedwater required in the steam generator 10, for example, a high-pressure feed pump or the like may be further provided downstream of the feedwater heater 25.

Further, the feedwater heater is arranged as appropriate depending on the temperature of the feedwater required in the steam generator 10. Therefore, there are cases where the feedwater heater is not provided or where a plurality of feedwater heaters are provided. Incidentally, when the feedwater heater is not provided, the configurations of the extraction steam pipe 40 and the discharge pipe 41 are not required.

Further, the feed pipe 39 is provided with a discharge pipe 42 for removing from the condensed water produced in the condenser 23, the amount of water condensed from the water vapor produced in the steam generator 10 and the combustor 30. Incidentally, in the discharge pipe 42, a flow rate regulating valve (not illustrated) that regulates the amount of water to be discharged is provided. The discharge pipe 42 is connected to the feed pipe 39 downstream of the feed pump 24, for example.

Here, the feedwater to be discharged from the discharge pipe 42 may be supplied to, for example, an external hot water utilization facility that utilizes hot water or another facility. Further, for example, the position at which the discharge pipe 42 is connected to the feed pipe 39 may be changed as appropriate depending on the hot water temperature required in the hot water utilization facility. For example, when high-temperature hot water is required, the discharge pipe 42 may be connected to the feed pipe 39 downstream of the feedwater heater 25.

Further, the steam equivalent to the water vapor produced in the steam generator 10 and the combustor 30 may be removed not only as condensed water but also as steam. In this case, the steam equivalent to the water vapor produced in the steam generator 10 and the combustor 30 may be removed as extraction steam from the high-pressure turbine 21 or the low-pressure turbine 22, for example. The removed steam is supplied, for example, to an external steam utilization facility that utilizes steam or another facility.

Incidentally, to the hot water utilization facility or steam utilization facility, for example, the amount of water that exceeds the amount of water condensed from the water vapor produced in the steam generator 10 and the combustor 30 may be supplied, or the amount of steam that exceeds the amount of water vapor produced in the steam generator 10 and the combustor 30 may be supplied. In this case, water equivalent to the excess feedwater or steam discharged to the outside is supplied to the condenser 23, for example.

Next, the operation of the steam turbine power generation facility 1 is explained.

In the steam generator 10, oxygen and hydrogen combust to produce water vapor (steam). Further, the feedwater supplied from the feedwater supply part 13 evaporates into steam by the heat of reaction generated by the combustion. The steam generated in the steam generator 10 is introduced into the high-pressure turbine 21 via the main steam pipe 35. That is, the entire amount of the water vapor, which is the combustion gas produced by the combustion of oxygen and hydrogen, is also introduced into the high-pressure turbine 21 together with the generated steam.

The steam introduced into the high-pressure turbine 21 rotates the high-pressure turbine 21 and then is discharged to the steam pipe 36. A portion of the steam discharged into the steam pipe 36 is introduced into the low-pressure turbine 22 as a cooling medium via the cooling medium supply pipe 37. The remainder of the steam discharged into the steam pipe 36 is introduced into the combustor 30.

In the combustor 30, water vapor is produced by the combustion of hydrogen and oxygen. The steam introduced into the combustor 30 is reheated by being mixed with the water vapor produced in the combustor 30, and is introduced into the low-pressure turbine 22. That is, the water vapor produced by the combustion and the introduced steam are introduced into the low-pressure turbine 22.

Here, the flow rate of the steam to be introduced into the low-pressure turbine 22 increases by the flow rate of the water vapor produced in the combustor 30. Further, the temperature of the steam discharged from the high-pressure turbine 21 increases as it is mixed with the high-temperature water vapor produced in the combustor 30. The temperature and the flow rate of the steam to be introduced into the low-pressure turbine 22 are adjusted by adjusting the combustion conditions of the combustor 30.

By increasing the temperature of the steam to be introduced into the low-pressure turbine 22 and further increasing the flow rate of the steam to be introduced into the low-pressure turbine 22, the thermal efficiency and output in the low-pressure turbine 22 increase. That is, by providing the combustor 30, the thermal efficiency and output increase.

The steam introduced into the low-pressure turbine 22 rotates the low-pressure turbine 22 and then is discharged to the exhaust pipe 38. The steam discharged to the exhaust pipe 38 is introduced into the condenser 23 to condense into condensed water. Incidentally, the power generator 50 is driven by the rotations of the high-pressure turbine 21 and the low-pressure turbine 22 to generate electricity.

The condensed water from the condenser 23 is pumped as feedwater by the feed pump 24 to be led to the feedwater supply part 13 of the steam generator 10 via the feed pipe 39. At this time, the feedwater flowing through the feed pipe 39 is heated in the feedwater heater 25 by the extraction steam from the low-pressure turbine 22.

As described above, according to the steam turbine power generation facility 1 in the first embodiment, the steam generator 10 that generates steam by the heat of reaction generated by the combustion of oxygen and hydrogen is provided, thereby making it possible to introduce the combustion gas (water vapor) produced by the combustion and the steam generated by the heat of reaction into the high-pressure turbine 21. Thereby, the exhaust heat from the steam generator 10 is utilized in the high-pressure turbine 21. Therefore, the heat loss due to exhaust heat from the steam generator 10 does not occur.

The combustor 30 that combusts hydrogen and oxygen is provided, thereby making it possible to produce water vapor and at the same time, to reheat the steam exhausted from the high-pressure turbine 21. Therefore, the temperature of the steam to be introduced into the low-pressure turbine 22 is higher than that of the steam exhausted from the high-pressure turbine 21. This improves the thermal efficiency of the heat cycle.

Further, the flow rate of the steam to be introduced into the low-pressure turbine 22 increases by the amount of steam produced in the combustor 30. As a result, the turbine output increases.

In the steam turbine power generation facility 1, the heat of reaction generated by the combustion of oxygen and hydrogen is utilized as a heat source, and thus the greenhouse effect gases such as carbon dioxide (CO₂) and nitrogen oxides (NO_x) are not emitted. Therefore, carbon neutrality can be achieved. Furthermore, the steam turbine power generation facility 1 does not emit any environmental emissions such as greenhouse effect gases, air pollutants, or water pollutants, and thus a zero-emission steam turbine power generation facility can be fabricated.

(Other Forms in the First Embodiment)

FIG. 2 and FIG. 3 are system diagrams that schematically illustrate other forms in the steam turbine power generation facility 1 in the first embodiment. FIG. 2 and FIG. 3 each illustrate an example where a plurality of feedwater heaters are provided.

As illustrated in FIG. 2, a feedwater heater 26 may be provided in the feed pipe 39 downstream of the feedwater heater 25. Extraction steam from the low-pressure turbine 22 is introduced into the feedwater heater 26 via an extraction steam pipe 40a. In this case, the extraction steam pipe 40a extracts steam from a turbine stage upstream of the extraction steam pipe 40. Therefore, the extraction steam to be introduced by the extraction steam pipe 40a has a higher temperature and pressure than the extraction steam to be introduced by the extraction steam pipe 40.

The extraction steam that has heated the feedwater in the feedwater heater 26 is introduced into the feedwater heater 25, for example, via a discharge pipe 41a. This configuration is suitable in the case where the temperature of the extraction steam to be discharged from the feedwater heater 26 is equal to or higher than that of the extraction steam to be introduced via the extraction steam pipe 40. This makes it possible to effectively utilize the extraction steam discharged from the feedwater heater 26.

As illustrated in FIG. 3, a feedwater heater 27 may be provided in the feed pipe 39 downstream of the feedwater heater 25. Extraction steam from the high-pressure turbine 21 is introduced into the feedwater heater 27 via an extraction steam pipe 40b. Therefore, the extraction steam to be introduced by the extraction steam pipe 40b has a higher temperature and pressure than the extraction steam to be introduced by the extraction steam pipe 40.

The extraction steam that has heated the feedwater in the feedwater heater 27 is introduced into the feedwater heater 25, for example, via a discharge pipe 41b. This configuration is suitable in the case where the temperature of the extraction steam to be discharged from the feedwater heater 27 is equal to or higher than that of the extraction steam to be introduced via the extraction steam pipe 40. This makes it possible to effectively utilize the extraction steam discharged from the feedwater heater 27.

As illustrated in FIG. 2 and FIG. 3, by providing a plurality of the feedwater heaters 25, 26, and 27, the temperature of the feedwater increases to improve the thermal efficiency of the heat cycle.

FIG. 4 is a system diagram schematically illustrating another form in the steam turbine power generation facility 1 in the first embodiment. As illustrated in FIG. 4, the another form in the steam turbine power generation facility 1 does not include the cooling medium supply pipe 37 that introduces a portion of the steam discharged from the high-pressure turbine 21 into the low-pressure turbine 22 as a cooling medium.

When the temperature of the steam to be introduced into the low-pressure turbine 22 from the combustor 30 is equal to or lower than the heat-resistant temperature of the components in the low-pressure turbine 22, for example, the steam turbine power generation facility can be configured without introducing the cooling medium into the low-pressure turbine 22.

In the other forms in the steam turbine power generation facility 1 as well, in addition to the operation and effects in the other forms, the same operation and effects as those of the steam turbine power generation facility 1 illustrated in FIG. 1 can be obtained.

Incidentally, in the other forms in the steam turbine power generation facility 1, the configuration in which the attemperator 11 is not provided in the extraction steam pipe 40 has been explained as an example, but depending on the extraction steam conditions, the attemperator 110 may be provided in the extraction steam pipe 40 as illustrated in FIG. 1. Further, the attemperator 110 is not limited to being provided in the extraction steam pipe 40, and may be provided in the extraction steam pipes 40a and 40b. Further, in the following embodiments as well, depending on the extraction steam conditions, the configuration in which the attemperator 110 is provided in the extraction steam pipe may be employed. Incidentally, in the case where the attemperator 110 is provided, the configurations of the feedwater lead-out pipe 111 and the feedwater introduction pipe 112 are also provided.

Second Embodiment

FIG. 5 is a system diagram schematically illustrating a configuration of a steam turbine power generation facility 2 in a second embodiment. Incidentally, in the following embodiment, the same components as those in the steam turbine power generation facility 1 in the first embodiment are denoted by the same reference numerals and symbols, and duplicated explanations are omitted or simplified.

The steam turbine power generation facility 2 in the second embodiment has a configuration in which the feedwater is heated by the steam discharged from the low-pressure turbine 22. The other configuration is the same as that of the steam turbine power generation facility 1 in the first embodiment. Therefore, the configuration that differs from the configuration of the steam turbine power generation facility 1 in the first embodiment is mainly explained here.

The steam turbine power generation facility 2 includes an exhaust pipe heat exchange part 60 that heats feedwater by the steam discharged from the low-pressure turbine 22. As illustrated in FIG. 5, the exhaust pipe heat exchange part 60 is provided in the exhaust pipe 38.

The feed pipe 39 that supplies feedwater from the condenser 23 to the steam generator 10 is provided via the exhaust pipe heat exchange part 60. As illustrated in FIG. 5, for example, the feed pipe 39 is configured to pass through the exhaust pipe heat exchange part 60 at a portion between the feed pump 24 and the feedwater heater 25. That is, the feedwater is heated in the exhaust pipe heat exchange part 60 upstream of the feedwater heater 25.

Incidentally, the discharge pipe 42 is connected to the feed pipe 39 between the feed pump 24 and the exhaust pipe heat exchange part 60, for example. Further, the method of discharging to the outside the water and steam equivalent to the water vapor produced in the steam generator 10 and the combustor 30, and the means of utilizing the water and steam discharged to the outside are as described in the first embodiment.

The feedwater flowing through the feed pipe 39 flows into the exhaust pipe heat exchange part 60 and exchanges heat with the steam flowing through the exhaust pipe 38. Through this heat exchange, the feedwater is heated by the steam. Meanwhile, the steam discharged from the low-pressure turbine 22 passes through the exhaust pipe heat exchange part 60, thereby releasing heat to the feedwater. Then, the temperature of the steam decreases down to the set temperature of the steam to be introduced into the condenser 23, for example.

Here, the configuration in which the feedwater heater 25 is provided downstream of the exhaust pipe heat exchange part 60 in the feed pipe 39 is applied to the case where the temperature of the feedwater heated in the exhaust pipe heat exchange part 60 is lower than that of the extraction steam to be introduced into the feedwater heater 25, for example.

Here, as illustrated in FIG. 5, the feed pipe 39 may be provided with a bypass pipe 45 that bypasses the exhaust pipe heat exchange part 60. That is, the bypass pipe 45 is provided so as not to pass through the exhaust pipe heat exchange part 60. The bypass pipe 45 is a pipe that connects the feed pipe 39 between the feed pump 24 and the exhaust pipe heat exchange part 60 and the feed pipe 39 between the exhaust pipe heat exchange part 60 and the feedwater heater 25. The feedwater flowing through the bypass pipe 45 is introduced into the feedwater heater 25 without passing through the exhaust pipe heat exchange part 60.

A flow rate regulating valve 46 is interposed in the bypass pipe 45. Providing the bypass pipe 45 makes it possible to adjust the temperature of the steam to be introduced into the condenser 23, for example. Incidentally, when the flow rate regulating valve 46 is closed, the entire amount of feedwater passes through the exhaust pipe heat exchange part 60 to be introduced into the feedwater heater 25.

Incidentally, although not illustrated, a check valve may be provided in the feed pipe 39, for example, between a downstream connecting portion that connects to the downstream end of the bypass pipe 45 and the exhaust pipe heat exchange part 60. This makes it possible to prevent the feedwater from flowing back from the downstream connecting portion into the feed pipe 39 when the feedwater flows through the bypass pipe 45.

According to the steam turbine power generation facility 2, when high-temperature steam is introduced into the low-pressure turbine 22 from the combustor 30, the temperature of the steam to be discharged from the low-pressure turbine 22 may be higher than that of the steam to be discharged from the low-pressure turbine 22 when the combustor 30 is not provided, for example. In such a case, high-temperature steam is introduced into the condenser 23, and thus, the thermal efficiency of the heat cycle decreases.

Thus, providing the exhaust pipe heat exchange part 60 makes it possible to increase the temperature of the feedwater by the steam to be discharged from the low-pressure turbine 22, and at the same time, to reduce the temperature of the steam to be introduced into the condenser 23 down to an appropriate temperature. This improves the thermal efficiency of the heat cycle.

Incidentally, in the steam turbine power generation facility 2, in addition to the above-described operation and effects, the same operation and effects as those of the steam turbine power generation facility 1 in the first embodiment described above can be obtained.

(Another Form in the Second Embodiment)

FIG. 6 is a system diagram schematically illustrating another form in the steam turbine power generation facility 2 in the second embodiment. The another form in the steam turbine power generation facility 2 differs from the configuration of the steam turbine power generation facility 2 illustrated in FIG. 5 in the configuration in which the feedwater is led out from the feed pipe 39 to the exhaust pipe heat exchange part 60 and the configuration in which the feedwater is introduced into the feed pipe 39 from the exhaust pipe heat exchange part 60.

As illustrated in FIG. 6, the another form in the steam turbine power generation facility 2 includes a feedwater lead-out pipe 61 that leads out feedwater from the feed pipe 39 to the exhaust pipe heat exchange part 60, and a feedwater introduction pipe 62 that introduces the feedwater heated in the exhaust pipe heat exchange part 60 into the feed pipe 39.

One end of the feedwater lead-out pipe 61 is connected to the feed pipe 39 between the feed pump 24 and the feedwater heater 25. The other end of the feedwater lead-out pipe 61 is connected to the exhaust pipe heat exchange part 60. A flow rate regulating valve 61a that regulates the flow rate of feedwater to be introduced into the exhaust pipe heat exchange part 60 is interposed in the feed pipe 61.

One end of the feedwater introduction pipe 62 is connected to the feed pipe 39 downstream of the position at which the feedwater lead-out pipe 61 is connected. Here, there is explained an example where one end of the feedwater introduction pipe 62 is connected to the feed pipe 39 between the feedwater heater 25 and the steam generator 10. The other end of the feedwater introduction pipe 62 is connected to the exhaust pipe heat exchange part 60. Incidentally, although not illustrated, a check valve may be provided in the feedwater introduction pipe 62. This makes it possible to prevent the feedwater from flowing back from the feed pipe 39 into the feedwater introduction pipe 62.

Incidentally, the discharge pipe 42 is connected to the feed pipe 39 between the feed pump 24 and a connecting portion of the feedwater lead-out pipe 61 with the feed pipe 39, for example.

When the flow rate regulating valve 61a is open, a portion of the feedwater flowing through the feed pipe 39 is led out to the feedwater lead-out pipe 61 to be introduced into the exhaust pipe heat exchange part 60. The feedwater heated in the exhaust pipe heat exchange part 60 is introduced into the feed pipe 39 again via the feedwater introduction pipe 62. The remainder of the feedwater is pumped through the feedwater heater 25 to the steam generator 10 via the feed pipe 39. In this case, as described above, the temperature of the steam discharged from the low-pressure turbine 22 decreases down to the set temperature of the steam to be introduced into the condenser 23, for example.

Incidentally, when the flow rate regulating valve 61a is closed, the entire amount of feedwater is pumped through the feedwater heater 25 to the steam generator 10 via the feed pipe 39.

Here, the configuration in which one end of the feedwater introduction pipe 62 is connected to the feed pipe 39 between the feedwater heater 25 and the steam generator 10 is suitable in the case where the temperature of the feedwater heated in the exhaust pipe heat exchange part 60 is higher than that of the feedwater heated in the feedwater heater 25, for example.

In the another form in the steam turbine power generation facility 2, in addition to the operation and effects in the another form, the same operation and effects as those of the steam turbine power generation facility 2 described above can be obtained.

Third Embodiment

FIG. 7 is a system diagram schematically illustrating a configuration of a steam turbine power generation facility 3 in a third embodiment. The steam turbine power generation facility 3 in the third embodiment includes an intermediate-pressure turbine 28 between the high-pressure turbine 21 and the low-pressure turbine 22. Further, the steam turbine power generation facility 3 in the third embodiment has a configuration in which feedwater is heated by the steam discharged from the intermediate-pressure turbine 28. The other configuration is the same as that of the steam turbine power generation facility 1 in the first embodiment. Therefore, the configuration that differs from the configuration of the steam turbine power generation facility 1 in the first embodiment is mainly explained here.

As illustrated in FIG. 7, in the flow direction of a steam flow, the intermediate-pressure turbine 28 is provided downstream of the high-pressure turbine 21. The high-pressure turbine 21, the intermediate-pressure turbine 28, the low-pressure turbine 22, and the power generator 50 are arranged, for example, on the same axis and are configured so that their rotors rotate integrally. Incidentally, the intermediate-pressure turbine 28 functions as a third steam turbine, and the low-pressure turbine 22 functions as a fourth steam turbine.

The steam outlet of the high-pressure turbine 21 is connected to the steam inlet of the intermediate-pressure turbine 28 via the steam pipe 36. The combustor 30 is interposed in the steam pipe 36, for example. Incidentally, the combustor 30 may also be provided at the steam inlet portion of the intermediate-pressure turbine 28.

Steam discharged from the combustor 30 is introduced into the steam inlet of the intermediate-pressure turbine 28 via the steam pipe 36. Further, a portion of the steam discharged from the high-pressure turbine 21 is introduced into the intermediate-pressure turbine 28 as a cooling medium via the cooling medium supply pipe 37. Incidentally, the temperature of the cooling medium is lower than that of the steam to be introduced into the intermediate-pressure turbine 28 from the combustor 30. Further, the temperature of the cooling medium is set, for example, to a temperature that can maintain the components of the intermediate-pressure turbine 28 at or below the heat-resistant temperature of the components.

The cooling medium is introduced into the intermediate-pressure turbine 28, thereby making it possible to cool the components of the intermediate-pressure turbine 28. This allows the steam that is introduced from the combustor 30 to be hotter.

The steam outlet of the intermediate-pressure turbine 28 is connected to the steam inlet of the low-pressure turbine 22 via a steam pipe 47. The steam outlet of the low-pressure turbine 22 is connected to the condenser 23 via the exhaust pipe 38.

Extraction steam from the intermediate-pressure turbine 28 is introduced into the feedwater heater 25 via the extraction steam pipe 40c. The feedwater flowing through the feed pipe 39 is heated by the extraction steam from the intermediate-pressure turbine 28 in the feedwater heater 25.

The steam turbine power generation facility 3 includes a steam pipe heat exchange part 70 that heats the feedwater by the steam discharged from the intermediate-pressure turbine 28. As illustrated in FIG. 7, the steam pipe heat exchange part 70 is provided in the steam pipe 47.

The feed pipe 39 that supplies feedwater from the condenser 23 to the steam generator 10 is provided via the steam pipe heat exchange part 70. As illustrated in FIG. 7, for example, the feed pipe 39 is configured to pass through the steam pipe heat exchange part 70 at a portion between the feed pump 24 and the feedwater heater 25. That is, the feedwater is heated in the steam pipe heat exchange part 70 upstream of the feedwater heater 25.

Incidentally, the discharge pipe 42 is connected to the feed pipe 39 between the feed pump 24 and the steam pipe heat exchange part 70, for example. Further, the method of discharging to the outside the water and steam equivalent to the water vapor produced in the steam generator 10 and the combustor 30, and the means of utilizing the water and steam discharged to the outside are as described in the first embodiment.

The feedwater flowing through the feed pipe 39 flows into the steam pipe heat exchange part 70 and exchanges heat with the steam flowing through the steam pipe 47. Through this heat exchange, the feedwater is heated by the steam. Meanwhile, the steam discharged from the intermediate-pressure turbine 28 passes through the steam pipe heat exchange part 70, thereby releasing heat to the feedwater. Then, the temperature of the steam decreases down to the set temperature of the steam to be introduced into the low-pressure turbine 22, for example.

Here, the configuration in which the feedwater heater 25 is provided downstream of the steam pipe heat exchange part 70 in the feed pipe 39 is applied to the case where the temperature of the feedwater heated in the steam pipe heat exchange part 70 is lower than that of the extraction steam to be introduced into the feedwater heater 25, for example.

Here, as illustrated in FIG. 7, the feed pipe 39 may be provided with a bypass pipe 48 that bypasses the steam pipe heat exchange part 70. That is, the bypass pipe 48 is provided so as not to pass through the steam pipe heat exchange part 70. The bypass pipe 48 is a pipe that connects the feed pipe 39 between the feed pump 24 and the steam pipe heat exchange part 70 and the feed pipe 39 between the steam pipe heat exchange part 70 and the feedwater heater 25. The feedwater flowing through the bypass pipe 48 is introduced into the feedwater heater 25 without passing through the steam pipe heat exchange part 70.

A flow rate regulating valve 49 is interposed in the bypass pipe 48. Providing the bypass pipe 48 makes it possible to adjust the temperature of the steam to be introduced into the low-pressure turbine 22. Incidentally, when the flow rate regulating valve 49 is closed, the entire amount of feedwater passes through the steam pipe heat exchange part 70 to be introduced into the feedwater heater 25.

Incidentally, although not illustrated, a check valve may be provided in the feed pipe 39, for example, between a downstream connecting portion that connects to the downstream end of the bypass pipe 48 and the steam pipe heat exchange part 70. This makes it possible to prevent the feedwater from flowing back from the downstream connecting portion into the feed pipe 39 when the feedwater flows through the bypass pipe 48.

According to the steam turbine power generation facility 3, when high-temperature steam is introduced into the intermediate-pressure turbine 28 from the combustor 30, the temperature of the steam to be discharged from the intermediate-pressure turbine 28 may exceed the set temperature of the steam to be introduced into the low-pressure turbine 22.

Thus, providing the steam pipe heat exchange part 70 makes it possible to increase the temperature of the feedwater by the steam to be discharged from the intermediate-pressure turbine 28 and at the same time, to reduce the temperature of the steam to be introduced into the low-pressure turbine 22 down to an appropriate temperature. The excess heat to be introduced into the low-pressure turbine 22 can be given to the feedwater, and therefore the thermal efficiency of the heat cycle improves.

Incidentally, in the steam turbine power generation facility 3, in addition to the above-described operation and effects, the same operation and effects as those of the steam turbine power generation facility 1 in the first embodiment described above can be obtained.

(Another Form in the Third Embodiment)

FIG. 8 is a system diagram schematically illustrating another form in the steam turbine power generation facility 3 in the third embodiment. The another form in the steam turbine power generation facility 3 differs from the configuration of the steam turbine power generation facility 3 illustrated in FIG. 7 in the configuration in which the feedwater is led out from the feed pipe 39 to the steam pipe heat exchange part 70 and the configuration in which the feedwater is introduced into the feed pipe 39 from the steam pipe heat exchange part 70.

As illustrated in FIG. 8, the another form in the steam turbine power generation facility 3 includes a feedwater lead-out pipe 71 that leads out feedwater from the feed pipe 39 to the steam pipe heat exchange part 70, and a feedwater introduction pipe 72 that introduces the feedwater heated in the steam pipe heat exchange part 70 into the feed pipe 39.

One end of the feedwater lead-out pipe 71 is connected to the feed pipe 39 between the feed pump 24 and the feedwater heater 25. The other end of the feedwater lead-out pipe 71 is connected to the steam pipe heat exchange part 70. A flow rate regulating valve 71a that regulates the flow rate of feedwater to be introduced into the steam pipe heat exchange part 70 is interposed in the feedwater lead-out pipe 71.

One end of the feedwater introduction pipe 72 is connected to the feed pipe 39 downstream of the position at which the feedwater lead-out pipe 71 is connected. Here, there is explained an example where one end of the feedwater introduction pipe 72 is connected to the feed pipe 39 between the feedwater heater 25 and the steam generator 10. The other end of the feedwater introduction pipe 72 is connected to the steam pipe heat exchange part 70. Incidentally, although not illustrated, a check valve may be provided in the feedwater introduction pipe 72. This makes it possible to prevent the feedwater from flowing back from the feed pipe 39 into the feedwater introduction pipe 72.

Incidentally, the discharge pipe 42 is connected to the feed pipe 39 between the feed pump 24 and the connecting portion of the feedwater lead-out pipe 71 with the feed pipe 39, for example.

When the flow rate regulating valve 71a is open, a portion of the feedwater flowing through the feed pipe 39 is led out to the feedwater lead-out pipe 71 to be led to the steam pipe heat exchange part 70. The feedwater heated in the steam pipe heat exchange part 70 is introduced into the feed pipe 39 again via the feedwater introduction pipe 72. The remainder of the feedwater is pumped through the feedwater heater 25 to the steam generator 10 via the feed pipe 39. In this case, as described previously, the temperature of the steam discharged from the intermediate-pressure turbine 28 decreases down to the set temperature of the steam to be introduced into the low-pressure turbine 22, for example.

Incidentally, when the flow rate regulating valve 71a is closed, the entire amount of feedwater is pumped through the feedwater heater 25 to the steam generator 10 via the feed pipe 39.

Here, the configuration in which one end of the feedwater introduction pipe 72 is connected to the feed pipe 39 between the feedwater heater 25 and the steam generator 10 is suitable in the case where the temperature of the feedwater heated in the steam pipe heat exchange part 70 is higher than that of the feedwater heated in the feedwater heater 25, for example.

In the another form in the steam turbine power generation facility 3, in addition to the operation and effects in the another form, the same operation and effects as those of the steam turbine power generation facility 3 described above can be obtained.

Fourth Embodiment

FIG. 9 is a system diagram schematically illustrating a configuration of a steam turbine power generation facility 4 in a fourth embodiment. In the steam turbine power generation facility 4 in the fourth embodiment, a combustor 80 is provided at the steam inlet portion of the high-pressure turbine 21. Further, a portion of the steam discharged from the steam generator 10 is introduced into the high-pressure turbine 21 as a cooling medium. The other configuration is the same as that of the steam turbine power generation facility 1 in the first embodiment. Therefore, the configuration that differs from the configuration of the steam turbine power generation facility 1 in the first embodiment is mainly explained here.

The combustor 80 combusts oxygen and hydrogen. The combustor 80 is provided at the steam inlet portion of the high-pressure turbine 21. The combustor 80 includes a hydrogen supply part 81 that supplies hydrogen, and an oxygen supply part 82 that supplies oxygen. In the combustor 80, water vapor is produced as a combustion gas. Incidentally, the combustor 80 functions as a second combustor.

Further, steam discharged from the steam generator 10 is introduced into the combustor 80 via the main steam pipe 35. The combustor 80 heats the introduced steam by the produced water vapor. Then, the water vapor produced in the combustor 80 is mixed with the introduced steam to be supplied to the high-pressure turbine 21.

Incidentally, the flow rates of oxygen and hydrogen to be supplied to the combustor 80 are adjusted as appropriate based on, for example, setting the temperature of the water vapor to be produced, or the like. The flow rates of oxygen and hydrogen are adjusted, for example, to achieve a stoichiometric mixture ratio (equivalence ratio of 1).

Into the high-pressure turbine 21, a portion of the steam discharged from the steam generator 10 is introduced as a cooling medium via a cooling medium supply pipe 85. One end of the cooling medium supply pipe 85 is connected to the main steam pipe 35 between the steam generator 10 and the combustor 80, for example. The other end of the cooling medium supply pipe 85 is connected to the cooling medium introducing portion of the high-pressure turbine 21.

Incidentally, although not illustrated, a flow rate regulating valve for regulating the flow rate of the cooling medium to be introduced into the high-pressure turbine 21 is interposed in the cooling medium supply pipe 85. The temperature of the cooling medium is lower than that of the steam to be introduced into the high-pressure turbine 21 from the combustor 80. The temperature of the cooling medium is set, for example, to a temperature that can maintain the components of the high-pressure turbine 21 at or below the heat-resistant temperature of the components.

The cooling medium is introduced into the high-pressure turbine 21, thereby making it possible to cool the components of the high-pressure turbine 21. This allows the steam that is introduced from the combustor 80 to be hotter.

In the steam turbine power generation facility 4, the combustor 80 that combusts hydrogen and oxygen is provided, thereby making it possible to produce water vapor and at the same time, to heat the steam discharged from the steam generator 10. As a result, the temperature of the steam to be introduced into the high-pressure turbine 21 is higher than that of the steam discharged from the steam generator 10. This improves the thermal efficiency of the heat cycle.

Further, the flow rate of the steam to be introduced into the high-pressure turbine 21 increases by the amount of steam produced in the combustor 80. Therefore, the turbine output increases.

Incidentally, in the steam turbine power generation facility 4, in addition to the above-described operation and effects, the same operation and effects as those of the steam turbine power generation facility 1 in the first embodiment described above can be obtained.

(Another Form in the Fourth Embodiment)

FIG. 10 is a system diagram schematically illustrating another form in the steam turbine power generation facility 4 in the fourth embodiment. As illustrated in FIG. 10, the another form in the steam turbine power generation facility 4 does not include the cooling medium supply pipe 85 that introduces a portion of the steam discharged from the steam generator 10 as a cooling medium into the high-pressure turbine 21. Further, the another form in the steam turbine power generation facility 4 does not include the cooling medium supply pipe 37 that introduces a portion of the steam discharged from the high-pressure turbine 21 as a cooling medium into the low-pressure turbine 22.

When the temperature of the steam to be introduced into the high-pressure turbine 21 from the combustor 80 is equal to or lower than the heat-resistant temperature of the components in the high-pressure turbine 21, for example, the steam turbine power generation facility 4 can be configured without introducing the cooling medium into the high-pressure turbine 21.

Further, when the temperature of the steam to be introduced into the low-pressure turbine 22 from the combustor 30 is equal to or lower than the heat-resistant temperature of the components in the low-pressure turbine 22, for example, the steam turbine power generation facility 4 can be configured without introducing the cooling medium into the low-pressure turbine 22.

In the another form in the steam turbine power generation facility 4 as well, the same operation and effects as those of the steam turbine power generation facility 4 described above can be obtained.

Fifth Embodiment

FIG. 11 is a system diagram schematically illustrating a configuration of a steam turbine power generation facility 5 in a fifth embodiment. The steam turbine power generation facility 5 in the fifth embodiment has a configuration obtained by adding a configuration of heating the feedwater by the steam discharged from the high-pressure turbine 21 to the configuration of the steam power generation facility 4 in the fourth embodiment illustrated in FIG. 9. Therefore, the configuration that differs from the configuration of the steam turbine power generation facility 4 in the fourth embodiment is mainly explained here.

As illustrated in FIG. 11, the steam turbine power generation facility 5 includes a steam pipe heat exchange part 90 that heats the feedwater by the steam discharged from the high-pressure turbine 21. The steam pipe heat exchange part 90 is provided in the cooling medium supply pipe 37.

The steam turbine power generation facility 5 includes a feedwater lead-out pipe 91 that leads out feedwater from the feed pipe 39 to the steam pipe heat exchange part 90, and a feedwater introduction pipe 92 that introduces the feedwater heated in the steam pipe heat exchange part 90 into the feed pipe 39.

One end of the feedwater lead-out pipe 91 is connected to the feed pipe 39 between the feed pump 24 and the feedwater heater 25. The other end of the feedwater lead-out pipe 91 is connected to the steam pipe heat exchange part 90. A flow rate regulating valve 91a that regulates the flow rate of feedwater to be introduced into the steam pipe heat exchange part 90 is interposed in the feedwater lead-out pipe 91.

One end of the feedwater introduction pipe 92 is connected to the feed pipe 39 downstream of the position at which the feedwater introduction pipe 91 is connected. Here, there is explained an example where one end of the feedwater introduction pipe 92 is connected to the feed pipe 39 between the feedwater heater 25 and the steam generator 10. The other end of the feedwater introduction pipe 92 is connected to the steam pipe heat exchange part 90. Incidentally, although not illustrated, a check valve may be provided in the feedwater introduction pipe 92. This makes it possible to prevent the feedwater from flowing back from the feed pipe 39 into the feedwater introduction pipe 92.

Incidentally, the discharge pipe 42 is connected to the feed pipe 39 between the feed pump 24 and the connecting portion of the feedwater lead-out pipe 91 with the feed pipe 39, for example. Further, the method of discharging to the outside the water and steam equivalent to the water vapor produced in the steam generator 10, the combustor 30, and the combustor 80 and the means of utilizing the water and steam discharged to the outside are as described in the first embodiment.

When the flow rate regulating valve 91a is open, a portion of the feedwater flowing through the feed pipe 39 is led out to the feedwater lead-out pipe 91 to be led to the steam pipe heat exchange part 90. The feedwater heated in the steam pipe heat exchange part 90 is introduced into the feed pipe 39 again via the feedwater introduction pipe 92. The remainder of the feedwater is pumped through the feedwater heater 25 to the steam generator 10 via the feed pipe 39. In this case, the steam discharged from the high-pressure turbine 21 and introduced into the cooling medium supply pipe 37 passes through the steam pipe heat exchange part 90, thereby releasing heat to the feedwater. Then, the temperature of the steam decreases down to the set temperature of the steam to be introduced into the low-pressure turbine as a cooling medium, for example.

Incidentally, when the flow rate regulating valve 91a is closed, the entire amount of feedwater is pumped through the feedwater heater 25 to the steam generator 10 via the feed pipe 39.

Here, the configuration in which one end of the feedwater introduction pipe 92 is connected to the feed pipe 39 between the feedwater heater 25 and the steam generator 10 is suitable in the case where the temperature of the feedwater heated in the steam pipe heat exchange part 90 is higher than that of the feedwater heated in the feedwater heater 25, for example.

According to the steam turbine power generation facility 5, when high-temperature steam is introduced into the high-pressure turbine 21 from the combustor 80, the temperature of the steam to be discharged from the high-pressure turbine 21 may exceed the set temperature of the cooling medium to be introduced into the low-pressure turbine 22 via the cooling medium supply pipe 37.

Thus, providing the steam pipe heat exchange part 90 makes it possible to increase the temperature of the feedwater by the steam to be discharged from the high-pressure turbine 21 and at the same time, to reduce the temperature of the cooling medium to be introduced into the low-pressure turbine 22 down to an appropriate temperature. By heating the feedwater, the thermal efficiency of the heat cycle improves.

Incidentally, in the steam turbine power generation facility 5, in addition to the above-described operation and effects, the same operation and effects as those of the steam turbine power generation facility 4 in the fourth embodiment described above can be obtained.

(Another Form in the Fifth Embodiment)

FIG. 12 is a system diagram schematically illustrating another form in the steam turbine power generation facility 5 in the fifth embodiment. The another form in the steam turbine power generation facility 5 differs from the configuration of the steam turbine power generation facility 5 illustrated in FIG. 11 in the configuration in which the feedwater is led out from the feed pipe 39 to the steam pipe heat exchange part 90 and the configuration in which the feedwater is introduced into the feed pipe 39 from the steam pipe heat exchange part 90.

As illustrated in FIG. 12, the feed pipe 39 that supplies feedwater from the condenser 23 to the steam generator 10 is provided via the steam pipe heat exchange part 90. The feed pipe 39 is configured to pass through the steam pipe heat exchange part 90 at a portion between the feed pump 24 and the feedwater heater 25, for example, as illustrated in FIG. 12. That is, the feedwater is heated in the steam pipe heat exchange part 90 upstream of the feedwater heater 25. Incidentally, the discharge pipe 42 is connected to the feed pipe 39 between the feed pump 24 and the steam pipe heat exchange part 90, for example.

The feedwater flowing through the feed pipe 39 flows into the steam pipe heat exchange part 90 and exchanges heat with the steam flowing through the cooling medium supply pipe 37. Through this heat exchange, the feedwater is heated by the steam. Meanwhile, the temperature of the steam decreases down to the set temperature of the steam to be introduced into the low-pressure turbine 22 as a cooling medium, for example.

Here, the configuration in which the feedwater heater 25 is provided downstream of the steam pipe heat exchange part 90 in the feed pipe 39 is applied to the case where the temperature of the feedwater heated in the steam pipe heat exchange part 90 is lower than that of the extraction steam to be introduced into the feedwater heater 25, for example.

Here, as illustrated in FIG. 12, the feed pipe 39 may be provided with a bypass pipe 95 that bypasses the steam pipe heat exchange part 90. That is, the bypass pipe 95 is provided so as not to pass through the steam pipe heat exchange part 90. The bypass pipe 95 is a pipe that connects the feed pipe 39 between the feed pump 24 and the steam pipe heat exchange part 90 and the feed pipe 39 between the steam pipe heat exchange part 90 and the feedwater heater 25. The feedwater flowing through the bypass pipe 95 is introduced into the feedwater heater 25 without passing through the steam pipe heat exchange part 90.

A flow rate regulating valve 96 is interposed in the bypass pipe 95. Providing the bypass pipe 95 makes it possible to adjust the temperature of the cooling medium to be introduced into the low-pressure turbine 22. Incidentally, when the flow rate regulating valve 96 is closed, the entire amount of feedwater passes through the steam pipe heat exchange part 90 to be introduced into the feedwater heater 25.

Incidentally, although not illustrated, a check valve may be provided in the feed pipe 39, for example, between the downstream connecting portion that connects to the downstream end of the bypass pipe 95 and the steam pipe heat exchange part 90. This makes it possible to prevent the feedwater from flowing back from the downstream connecting portion into the feed pipe 39 when the feedwater flows through the bypass pipe 95.

Here, in the another form in the steam turbine power generation facility 5, an example where the feed pipe 39 passes through the steam pipe heat exchange part 90 between the feed pump 24 and the feedwater heater 25 has been explained, but this form is not limited to this configuration.

FIG. 13 is a system diagram schematically illustrating another form in the steam turbine power generation facility 5 in the fifth embodiment. As illustrated in FIG. 13, the feed pipe 39 may pass through the steam pipe heat exchange part 90 at a portion between the feedwater heater 25 and the steam generator 10.

This configuration is suitable in the case where the temperature of the feedwater heated in the steam pipe heat exchange part 90 is higher than that of the feedwater heated in the feedwater heater 25, for example.

In the other forms in the steam turbine power generation facility 5 illustrated in FIG. 12 and FIG. 13, in addition to the operation and effects in the other forms, the same operation and effects as those of the steam turbine power generation facility 5 described above can be obtained.

Sixth Embodiment

FIG. 14 is a system diagram schematically illustrating a configuration of a steam turbine power generation facility 6 in a sixth embodiment. The steam turbine power generation facility 6 in the sixth embodiment has a configuration obtained by removing the configurations of the combustor 30 and the cooling medium supply pipe 37 from the configuration of the steam turbine power generation facility 4 in the fourth embodiment illustrated in FIG. 9.

As illustrated in FIG. 14, the steam turbine power generation facility 6 includes the steam generator 10, the steam turbine system 20, and the power generator 50 as main components. The steam turbine system 20 includes the high-pressure turbine 21, the low-pressure turbine 22, the combustor 80, the condenser 23, the feed pump 24, and the feedwater heater 25.

Incidentally, the high-pressure turbine 21 functions as a first steam turbine, and the low-pressure turbine 22 functions as a second steam turbine. The combustor 80 functions as a first combustor.

The combustor 80 is provided at the steam inlet portion of the high-pressure turbine 21. Incidentally, the combustor 80 is as explained in the fourth embodiment.

A portion of the steam discharged from the steam generator 10 is introduced as a cooling medium into the high-pressure turbine 21 via the cooling medium supply pipe 85. The steam outlet of the high-pressure turbine 21 and the steam inlet of the low-pressure turbine 22 are connected by the steam pipe 36. The steam discharged from the high-pressure turbine 21 is introduced into the low-pressure turbine 22 via the steam pipe 36.

The operation and effects obtained by providing the combustor 80 that combusts hydrogen and oxygen in the steam turbine power generation facility 6 are as explained in the fourth embodiment. Further, the operation and effects obtained by providing the steam generator 10 are as explained in the first embodiment.

In the steam turbine power generation facility 6 as well, the heat of reaction generated by the combustion of oxygen and hydrogen is utilized as a heat source, and thus the greenhouse effect gases such as carbon dioxide (CO₂) and nitrogen oxides (NO_x) are not emitted. Therefore, carbon neutrality can be achieved. Furthermore, the steam turbine power generation facility 6 does not emit any environmental emissions such as greenhouse effect gases, air pollutants, or water pollutants, and thus a zero-emission steam turbine power generation facility can be fabricated.

(Another Form in the Sixth Embodiment)

FIG. 15 is a system diagram schematically illustrating another form in the steam turbine power generation facility 6 in the sixth embodiment. As illustrated in FIG. 15, the another form in the steam turbine power generation facility 6 does not include the cooling medium supply pipe 85 that introduces a portion of the steam discharged from the steam generator 10 as a cooling medium into the high-pressure turbine 21.

When the temperature of the steam to be introduced into the high-pressure turbine 21 from the combustor 80 is equal to or lower than the heat-resistant temperature of the components in the high-pressure turbine 21, for example, the steam turbine power generation facility can be configured without introducing the cooling medium into the high-pressure turbine 21.

In the another form in the steam turbine power generation facility 6 as well, the same operation and effects as those of the steam turbine power generation facility 6 described above can be obtained.

Seventh Embodiment

FIG. 16 is a system diagram schematically illustrating a configuration of a steam turbine power generation facility 7 in a seventh embodiment. The steam turbine power generation facility 7 in the seventh embodiment has a configuration obtained by adding the configuration of heating the feedwater by the steam discharged from the high-pressure turbine 21 to the configuration of the steam turbine power generation facility 6 in the sixth embodiment illustrated in FIG. 14. Therefore, the configuration that differs from the configuration of the steam turbine power generation facility 6 in the sixth embodiment is mainly explained here.

As illustrated in FIG. 16, the steam turbine power generation facility 7 includes a steam pipe heat exchange part 100 that heats the feedwater by the steam discharged from the high-pressure turbine 21. The steam pipe heat exchange part 100 is provided in the steam pipe 36.

The steam turbine power generation facility 7 includes a feedwater lead-out pipe 101 that leads out feedwater from the feed pipe 39 to the steam pipe heat exchange part 100, and a feedwater introduction pipe 102 that introduces the feedwater heated in the steam pipe heat exchange part 100 into the feed pipe 39.

One end of the feedwater lead-out pipe 101 is connected to the feed pipe 39 between the feed pump 24 and the feedwater heater 25. The other end of the feedwater lead-out pipe 101 is connected to the steam pipe heat exchange part 100. A flow rate regulating valve 101a that regulates the flow rate of feedwater to be introduced into the steam pipe heat exchange part 100 is interposed in the steam pipe heat exchange part 101.

One end of the feedwater introduction pipe 102 is connected to the feed pipe 39 downstream of the position at which the feedwater introduction pipe 101 is connected. Here, there is explained an example where one end of the feedwater introduction pipe 102 is connected to the feed pipe 39 between the feedwater heater 25 and the steam generator 10. The other end of the feedwater introduction pipe 102 is connected to the steam pipe heat exchange part 100. Incidentally, although not illustrated, a check valve may be provided in the feedwater introduction pipe 102. This makes it possible to prevent the feedwater from flowing back from the feed pipe 39 into the feedwater introduction pipe 102.

Incidentally, the discharge pipe 42 is connected to the feed pipe 39 between the feed pump 24 and the connecting portion of the feedwater lead-out pipe 101 with the feed pipe 39, for example. Further, the method of discharging to the outside the water and steam equivalent to the water vapor produced in the steam generator 10 and the combustor 80 and the means of utilizing the water and steam discharged to the outside are as described in the first embodiment.

When the flow rate regulating valve 101a is open, a portion of the feedwater flowing through the feed pipe 39 is led out to the feedwater lead-out pipe 101 to be led to the steam pipe heat exchange part 100. The feedwater heated in the steam pipe heat exchange part 100 is introduced into the feed pipe 39 again via the feedwater introduction pipe 102. The remainder of the feedwater is pumped through the feedwater heater 25 to the steam generator 10 via the feed pipe 39. In this case, the steam discharged from the high-pressure turbine 21 passes through the steam pipe heat exchange part 100, thereby releasing heat to the feedwater. Then, the temperature of the steam decreases down to the set temperature of the steam to be introduced into the low-pressure turbine 22, for example. The steam that has passed through the steam pipe heat exchange part 100 is introduced into the low-pressure turbine 22.

Incidentally, when the flow rate regulating valve 101a is closed, the entire amount of feedwater is pumped through the feedwater heater 25 to the steam generator 10 via the feed pipe 39.

Here, the configuration in which one end of the feedwater introduction pipe 102 is connected to the feed pipe 39 between the feedwater heater 25 and the steam generator 10 is suitable in the case where the temperature of the feedwater heated in the steam pipe heat exchange part 100 is higher than that of the feedwater heated in the feedwater heater 25, for example.

According to the steam turbine power generation facility 7, when high-temperature steam is introduced into the high-pressure turbine 21 from the combustor 80, the temperature of the steam to be discharged from the high-pressure turbine 21 may exceed the set temperature of the steam to be introduced into the low-pressure turbine 22.

Thus, providing the steam pipe heat exchange part 100 makes it possible to increase the temperature of the feedwater by the steam to be discharged from the high-pressure turbine 21 and at the same time, to reduce the temperature of the steam to be introduced into the low-pressure turbine 22 down to an appropriate temperature. The excess heat to be introduced into the low-pressure turbine 22 can be given to the feedwater, and therefore the thermal efficiency of the heat cycle improves.

Incidentally, in the steam turbine power generation facility 7, in addition to the above-described operation and effects, the same operation and effects as those of the steam turbine power generation facility 6 in the sixth embodiment described above can be obtained.

(Another Form in the Seventh Embodiment)

FIG. 17 is a system diagram schematically illustrating another form in the steam turbine power generation facility 7 in the seventh embodiment. The another form in the steam turbine power generation facility 7 differs from the configuration of the steam turbine power generation facility 7 illustrated in FIG. 16 in the configuration in which the feedwater is led out from the feed pipe 39 to the steam pipe heat exchange part 100 and the configuration in which the feedwater is introduced into the feed pipe 39 from the steam pipe heat exchange part 100.

As illustrated in FIG. 17, the feed pipe 39 that supplies feedwater from the condenser 23 to the steam generator 10 is provided via the steam pipe heat exchange part 100. The feed pipe 39 is configured to pass through the steam pipe heat exchange part 100 at a portion between the feed pump 24 and the feedwater heater 25, for example, as illustrated in FIG. 17. That is, the feedwater is heated in the steam pipe heat exchange part 100 upstream of the feedwater heater 25. Incidentally, the discharge pipe 42 is connected to the feed pipe 39 between the feed pump 24 and the steam pipe heat exchange part 100, for example.

The feedwater flowing through the feed pipe 39 flows into the steam pipe heat exchange part 100 and exchanges heat with the steam flowing through the steam pipe 36. Through this heat exchange, the feedwater is heated by the steam. Meanwhile, the temperature of the steam decreases down to the set temperature of the steam to be introduced into the low-pressure turbine 22, for example.

Here, the configuration in which the feedwater heater 25 is provided downstream of the steam pipe heat exchange part 100 in the feed pipe 39 is applied to the case where the temperature of the feedwater heated in the steam pipe heat exchange part 100 is lower than that of the extraction steam to be introduced into the feedwater heater 25, for example.

Here, as illustrated in FIG. 17, the feed pipe 39 may be provided with a bypass pipe 105 that bypasses the steam pipe heat exchange part 100. That is, the bypass pipe 105 is provided so as not to pass through the steam pipe heat exchange part 100. The bypass pipe 105 is a pipe that connects the feed pipe 39 between the feed pump 24 and the steam pipe heat exchange part 100 and the feed pipe 39 between the steam pipe heat exchange part 100 and the feedwater heater 25. The feedwater flowing through the bypass pipe 105 is introduced into the feedwater heater 25 without passing through the steam pipe heat exchange part 100.

A flow rate regulating valve 106 is interposed in the bypass pipe 105. Providing the bypass pipe 105 makes it possible to adjust the temperature of the cooling medium to be introduced into the low-pressure turbine 22. Incidentally, when the flow rate regulating valve 106 is closed, the entire amount of feedwater passes through the steam pipe heat exchange part 100 to be introduced into the feedwater heater 25.

Incidentally, although not illustrated, a check valve may be provided in the feed pipe 39, for example, between the downstream connecting portion that connects to the downstream end of the bypass pipe 105 and the steam pipe heat exchange part 100. This makes it possible to prevent the feedwater from flowing back from the downstream connecting portion into the feed pipe 39 when the feedwater flows through the bypass pipe 105.

Here, in the another form in the steam turbine power generation facility 7, an example where the feed pipe 39 passes through the steam pipe heat exchange part 100 between the feed pump 24 and the feedwater heater 25 has been explained, but this form is not limited to this configuration.

FIG. 18 is a system diagram schematically illustrating another form in the steam turbine power generation facility 7 in the seventh embodiment. As illustrated in FIG. 18, the feed pipe 39 may pass through the steam pipe heat exchange part 100 at a portion between the feedwater heater 25 and the steam generator 10.

This configuration is suitable in the case where the temperature of the feedwater heated in the steam pipe heat exchange part 100 is higher than that of the feedwater heated in the feedwater heater 25, for example.

In the other forms in the steam turbine power generation facility 7 illustrated in FIG. 17 and FIG. 18, in addition to the operation and effects in the other forms, the same operation and effects as those of the steam turbine power generation facility 7 described above can be obtained.

Here, the configuration including a plurality of the feedwater heaters 25, 26, and 27 in the other forms in the steam turbine power generation facility 1 in the first embodiment illustrated in FIG. 2 and FIG. 3 may be applied to the steam turbine power generation facility 2 in the second embodiment to the steam turbine power generation facility 7 in the seventh embodiment described above.

The operation and effects obtained by providing a plurality of the feedwater heaters 25, 26, and 27 in the steam turbine power generation facility 2 in the second embodiment to the steam turbine power generation facility 7 in the seventh embodiment are the same as those obtained by providing a plurality of the feedwater heaters 25, 26, and 27 in the other forms in the steam turbine power generation facility 1 in the first embodiment illustrated in FIG. 2 and FIG. 3.

According to the embodiments explained above, using oxygen-hydrogen combustion makes it possible to reduce heat loss and to increase efficiency in the steam generator, and at the same time, to prevent emissions of greenhouse effect gases and the like.

While certain embodiments of the present invention have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel methods described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the methods described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.

Claims

1. A steam turbine power generation facility using oxygen-hydrogen combustion, comprising: a steam generator that generates steam by heat of reaction generated by combustion of oxygen and hydrogen;a first steam turbine into which steam is introduced from the steam generator;a first combustor into which steam discharged from the first steam turbine is introduced and that combusts oxygen and hydrogen to reheat the introduced steam;a second steam turbine into which steam discharged from the first combustor is introduced; anda condenser that condenses steam discharged from the second steam turbine.

2. The steam turbine power generation facility using oxygen-hydrogen combustion according to claim 1, wherein a portion of the steam discharged from the first steam turbine is introduced into the second steam turbine as a cooling medium.

3. The steam turbine power generation facility using oxygen-hydrogen combustion according to claim 2, further comprising: an exhaust pipe heat exchange part that is provided in an exhaust pipe that leads steam from the second steam turbine to the condenser, and the exhaust pipe heat exchange part that heats feedwater to be supplied from the condenser to the steam generator by the steam discharged from the second steam turbine.

4. The steam turbine power generation facility using oxygen-hydrogen combustion according to claim 2, wherein the second steam turbine is formed of a third steam turbine and a fourth steam turbine into which steam having a lower pressure than steam to be introduced into the third steam turbine is introduced,steam discharged from the first combustor is introduced into the third steam turbine,a portion of the steam discharged from the first steam turbine is introduced into the third steam turbine as a cooling medium,steam discharged from the third steam turbine is introduced into the fourth steam turbine, andsteam discharged from the fourth steam turbine is introduced into the condenser,the steam turbine power generation facility further comprising:a steam pipe heat exchange part that is provided in a steam pipe that supplies steam from the third steam turbine to the fourth steam turbine, and the steam pipe heat exchange part that heats feedwater to be supplied from the condenser to the steam generator by the steam discharged from the third steam turbine.

5. The steam turbine power generation facility using oxygen-hydrogen combustion according to claim 1, further comprising: a second combustor into which steam is introduced from the steam generator and that combusts oxygen and hydrogen to heat the introduced steam, whereinsteam discharged from the second combustor is introduced into the first steam turbine.

6. The steam turbine power generation facility using oxygen-hydrogen combustion according to claim 5, wherein a portion of the steam discharged from the steam generator is introduced into the first steam turbine as a cooling medium, anda portion of the steam discharged from the first steam turbine is introduced into the second steam turbine as a cooling medium.

7. The steam turbine power generation facility using oxygen-hydrogen combustion according to claim 6, further comprising: a steam pipe heat exchange part that is provided in a cooling medium supply pipe that introduces a portion of the steam discharged from the first steam turbine as a cooling medium into the second steam turbine, and the steam pipe heat exchange part that heats feedwater to be supplied from the condenser to the steam generator by the steam discharged from the first steam turbine.

8. A steam turbine power generation facility using oxygen-hydrogen combustion, comprising: a steam generator that generates steam by heat of reaction generated by combustion of oxygen and hydrogen;a first combustor into which steam is introduced from the steam generator and that combusts oxygen and hydrogen to heat the introduced steam;a first steam turbine into which steam discharged from the first combustor is introduced;a second steam turbine into which steam discharged from the first steam turbine is introduced; anda condenser that condenses steam discharged from the second steam turbine.

9. The steam turbine power generation facility using oxygen-hydrogen combustion according to claim 8, wherein a portion of the steam discharged from the steam generator is introduced into the first steam turbine as a cooling medium.

10. The steam turbine power generation facility using oxygen-hydrogen combustion according to claim 9, further comprising: a steam pipe heat exchange part that is provided in a steam pipe that supplies steam from the first steam turbine to the second steam turbine, and the steam pipe heat exchange part that heats feedwater to be supplied from the condenser to the steam generator by the steam discharged from the first steam turbine.